Enzyme solubilized collagen will be used as a vehicle for delivery of a variety of drugs useful in controlling diseases of the eyes. Films and cylinders of the purified collagen material will be prepared by casting and air-drying. Various drugs (pilocarpine, tetracycline, methylprednisolone, acetazolamide) will be incorporated in the films by either entrapment, electrostatic bonding or, in the future, co-valent bonding. Modifications of collagen will be made to alter either carboxyl or amino groups, and thereby enhance electrostatic bonding of either negatively or positively charged drug molecules. Cross-linking will be done to slow drug release from entrapped or electrostatically bonded films. Biologic tests will be done in rabbits and cats and compared with conventional modes of drug delivery. Clinical efficacy of collagen-pilocarpine films will be determined.